Simplify the following expression: $k = \dfrac{p - 9}{5p - 9} - \dfrac{-4p - 20}{5p - 9}$
Since the expressions have the same denominator we simply subtract the numerators: $k = \dfrac{p - 9 - (-4p - 20)}{5p - 9}$ Distribute the negative sign: $k = \dfrac{p - 9 + 4p + 20}{5p - 9}$ Combine like terms: $k = \dfrac{5p + 11}{5p - 9}$